Macular degeneration is the result of damage to the rod and cone cells of the macula, a small spot near the center of the retina, the part of the eye needed for sharp, central vision, said Dr. Emily Chew, a deputy director at the National Eye Institute. It’s the leading cause of blindness among Americans, she said.

There are two types of macular degeneration, Chew explained.

“The wet kind is caused by a growth of abnormal blood vessels in the eye that can leak and cause swelling. With this type, vision trouble often comes on suddenly,” she said.

“The dry kind is caused by a slow withering away of the tissues in the eye and the symptoms come on gradually,” she said, adding that the first symptom is typically trouble adjusting vision when moving from bright light into low light.

Chew said the first signs of the disease, yellow spots on the retina called drusen, usually appear after age 50 regardless of the type of macular degeneration. They don’t cause any symptoms but doctors can flag them during an eye exam years before vision begins to deteriorate.

People over 50, smokers and Caucasians are at greatest risk for the disease, and Chew noted that it’s rare among African Americans. Getting regular checkups is the best prevention, she said, and the best way to spot the condition early enough to treat. Wet macular degeneration can be treated with medications injected directly into the eye but there are no good treatments for the dry type, she said.

Someone in the early stages can help slow their loss of vision by eating lots of leafy green vegetables and avoiding cigarette smoke, Chew said. Eating two portions of fish a week has also been shown to preserve vision. And studies show that taking over-the-counter vitamins that include vitamin C and E, zinc and the micronutrients lutein and zeaxanthin, can help maintain or even improve eyesight for at least five years after diagnosis.

After being asked if macular degeneration would eventually leave her blind, Barr replied, "yeah."

"My vision is closing in now. It’s something weird. But there are other weird things. That one’s harsh, ’cause I read a lot, and then I thought, ‘Well, I guess I could hire somebody to read for me and read to me,'" she added. "I just try and enjoy vision as much as possible -- y’know, living it up."